Instrumenting High Reliability Electric Submersible Pumps

ABSTRACT

Instrumentation for high reliability electric submersible pumps (ESPs) is provided. Comprehensive sensors placed throughout ESP components enable monitoring, analysis, and intervention to improve performance of ESP components and provide high reliability and long life for components. Example ESP sensors used to protectively monitor an ESP string may include electrical current leakage detectors, temperature sensors at the pothead, fiber optics used as distributed temperature sensors in the motor stator and windings of the motor, water cut sensors to determine quality of hydrocarbon being produced, tachometer and torque sensors to detect the speed of rotating shafts of the motors and pumps, temperature and vibration sensors for rotor bearings and thrust members, and wye-point imbalance detectors for balancing electrical loads on the three phases in a wye system. Interpretation and control modules analyze the sensor input and apply actions that improve performance and lengthen lifespan of components.

RELATED APPLICATIONS

This patent application claims the benefit of priority to U.S. Provisional Patent Application No. 61/625,651 filed Apr. 17, 2012 and incorporated herein by reference in its entirety.

BACKGROUND

In artificial lift for the production of hydrocarbons and other resources, especially for subsea operations, it is important to increase the reliability of electric submersible pumps (ESPs) and their associated components (hereinafter, “ESP strings”) because the cost of intervention and repair can be very great. Conventional downhole monitoring to help avoid repairs is limited to the intake location and the discharge location of a conventional ESP string and measures only pressure, temperature, and vibration at the intake and discharge locations of the ESP string. Data from such conventional monitoring is sent to surface equipment for conventional interpretation, but offers only a rudimentary view of problems that may be occurring along the ESP string.

SUMMARY

Instrumentation for high reliability electric submersible pumps (ESPs) is provided. An example system includes an ESP string, a sensor associated with a shaft bearing or a rotor bearing of each section of the ESP string, a monitoring module for dynamically tracking data of each sensor, and a control module for changing an operating parameter of the ESP string based on the dynamic tracking of the sensor data. Embedded fiber optics can monitor distributed temperatures of motor coils and can also multiplex sensor data sent to the surface. Sensors may monitor bearing temperatures, bearing vibration, stator temperatures, distributed temperature profiles, power cable temperatures, shaft RPM, shaft torque, water cut, water ingress, fluid chemistry, bellows pressure, thrust bearing temperature, strain, and wear; electrical current leakage, and wye-point electrical phase imbalance. This summary section is not intended to give a full description of instrumenting high reliability electric submersible pumps. A detailed description with example embodiments follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an example electric submersible pump (ESP) string, with running fiber optic strand to monitor components.

FIG. 2 is a diagram of an example pump component of the ESP string, with thrust member.

FIG. 3 is a diagram of an example submersible motor arrayed with sensors for high reliability.

FIG. 4 is a diagram of an example protector arrayed with sensors for high reliability.

FIG. 5 is a diagram of an example thrust bearing assembly arrayed with sensors for high reliability.

FIG. 6 is a diagram of an example pump and pump intake arrayed with sensors for high reliability.

FIG. 7 is a block diagram of an example high reliability engine.

FIG. 8 is a block diagram of an example device for hosting the high reliability engine.

FIG. 9 is a flow diagram of an example method of improving performance and reliability of an ESP string.

DETAILED DESCRIPTION

This disclosure describes instrumenting high reliability electric submersible pumps (ESPs). An example system described herein provides high reliability ESP strings that have comprehensive sensor features and enhanced interpretation of the comprehensive sensors. The comprehensive sensor deployment enables enhanced monitoring, analysis, and control of many parts of the ESP string, not just the intake and discharge locations, and provides extended lifespan of components. In the description below, the terms “control” and “intervention” (or “intervene”) are used interchangeably. The example system includes new tools providing various enhanced monitoring and intervention capabilities for an ESP string.

Overview

An example ESP string is outfitted with numerous sensors throughout to provide improved operation and high reliability. The example submersible motor may include current leakage sensor(s) to detect grounding or loss of electrical current at likely locations, temperature sensor(s) at the pothead, fiber optics used as distributed temperature sensor(s) in the stator, e.g., for monitoring temperature along coil sections in the windings of the motor; water cut sensor(s) to determine quality of a hydrocarbon being produced, RPM and torque sensor(s) to detect the speed of rotating shafts of the motor(s) and/or pump(s), temperature and/or vibration sensor(s) applied to rotor bearings and thrust members, and wye-point imbalance detector(s) for balancing electrical loads on the three phases in a wye system.

Surface equipment measures and analyzes detected electrical current leakage. Temperature and vibration can be measured and monitored at multiple rotor bearing locations. One or more temperature profiles can be obtained along motor lead extension (MLE) cables using fiber optic or RTDs at potheads. The water cut sensors for oil purity may be used at multiple locations to also identify water ingress.

Example Systems

FIG. 1 shows an example submersible pumping system 20, with example sensor leads 18 connected internally to sensors arrayed within the pumping system 20. Submersible pumping system 20 may include a variety of sections and components depending on the particular application or environment in which it is used. Examples of components utilized in pumping system 20 include at least one submersible pump 22, at least one submersible motor 24, and one or more motor protectors 26 that are coupled together to form stages, sections, or segments of the submersible pumping system 20, referred to as an electric submersible pump (ESP) string 20.

In the example system shown, submersible pumping system 20 is designed for deployment in a well 28 within a geological formation 30 containing desirable production fluids, such as petroleum. A wellbore 32 is drilled into formation 30, and, in at least some applications, is lined with a wellbore casing 34. Perforations 36 are formed through wellbore casing 34 to enable flow of fluids between the surrounding formation 30 and the wellbore 32.

Submersible pumping system 20 is deployed in wellbore 32 by a deployment system 38 that may have a variety of configurations. For example, deployment system 38 may comprise tubing 40, such as coiled tubing or production tubing, connected to submersible pump 22 by a connector 42. Power is provided to the at least one submersible motor 24 via a power cable 44. The submersible motor 24, in turn, powers submersible pump 22 which can be used to draw in production fluid through a pump intake 46. Within submersible pump 22, a plurality of impellers is rotated to pump or produce the production fluid through, for example, tubing 40 to a desired collection location which may be at a surface 48 of the Earth.

The illustrated submersible pumping system 20 is only one example of many types of submersible pumping systems that can benefit from the features described herein. For example, multiple pump stages and other components can be added to the pumping system, and other deployment systems may be used. Additionally, the production fluids may be pumped to the collection location through tubing 40 or through an annulus around the deployment system 38. The submersible pump or pumps 22 can also utilize different types of stages, such as mixed flow stages or radial flow stages.

FIG. 2 shows a cross-sectional view of one example embodiment of a submersible pump 22. FIG. 2 is only one example of submersible pump construction provided to show example sensor placement. In this embodiment, submersible pump 22 comprises a plurality of stages, such as stages 50 and 50′. Each stage 50 comprises an impeller 52 coupled to a shaft 54 rotatable about a central axis 56. Rotation of shaft 54 by submersible motor 24 causes impellers 52 to rotate within an outer pump housing 58. Each impeller 52 draws fluid in through an impeller or stage intake 60 and routes the fluid along an interior impeller passageway 62 before discharging the fluid through an impeller outlet 64 and into an axially adjacent diffuser 66. The interior passageway 62 is defined by the shape of an impeller housing 68, and housing 68 may be formed to create an impeller for a floater stage, as illustrated in FIG. 2, or for a compression stage. Additionally, the impeller housing 68 may be designed to create a mixed flow stage, a radial flow stage, or another suitable stage style for use in submersible pump 22.

In FIG. 2, an inner thrust member 70, such as a thrust washer, is positioned to resist thrust loads, i.e., to resist downthrust loads created by the rotating impeller 52. In this example embodiment, thrust washer 70 may be positioned in the profile of an impeller feature 72, such as a recess formed in an upper portion of impeller housing 68. The thrust washer 70 may be disposed between the impeller 52 and a radially inward portion 74 of the next adjacent upstream diffuser 66. In an implementation, at least one sensor 76 may be placed near, against, or within the thrust member 70 and wired through stationary parts of the diffuser housing, such as radially inward portion 74. Temperature, load, and position or proximity sensors may be applied to a thrust bearing 70 to monitor load or strain on the thrust bearing 70 or proximity of a runner to the a thrust bearing 70. The sensor(s) may monitor the condition or aging of the thrust bearing, as well as load characteristics, e.g., for purposes of adjusting the load to spare the thrust bearing or to lengthen the lifespan of the thrust bearing.

FIG. 3 shows an example motor 24, which may power one or more components of an ESP string 20. For example, in one scenario, the example motor 24 may power multiple pump stages. The example motor 24 has various hardware components and associated sensors. The example motor 24 may have a motor head 302, a motor base 304, and an outer housing 306. A rotor 308, supported by rotor bearings 310, drives rotation of a shaft 312. A stator 314 with laminations provides a rotating magnetic field to drive the rotor 308.

The stator 314 has windings 316, which create electromagnetic fields when electricity flows. The rotor 308 may also have windings 316, to induce electromagnetic fields that interact with the electromagnetic fields of the stator 314. Alternatively, the rotor 308 may have permanent magnets instead of windings 316. The motor 24 may have other features, such as a drain and fill valve 318 for motor oil, such as dielectric oil. A coupling 320 at the motor head 302 connects with a pump 22 or a protector 26. Bearings for the shaft 312 may have associated thrust members 322 or a thrust ring to bear the axial load generated by the thrust of one or more operating pumps 22. Electrically, the motor 24 may have a power cable extension 324 that connects to a terminal 326.

Various types of sensors may be included in the ESP string 20 to monitor many aspects of the above components. The rotor 308, for example, may have a rotor temperature sensor 328. There may also be a pothead temperature sensor 330. Each bearing, such as the rotor bearings or a thrust bearing 322 may have a bearing temperature sensor 332. A fiber optic strand acting as a distributed temperature sensor 334 may be place in the stator 314.

In an implementation, the example system measures distributed temperature 334 via fiber optics, and also includes vibration sensors 336 at multiple locations along the ESP string 20. For example, an example system 20 may deploy distributed temperature sensing 334 and vibration sensors 336 mainly at pump bearings 604 & 606 and rotor bearings, such as bearing 322. In an implementation, an example system 20 makes measurements using fiber optics that are placed internally, e.g., in the motor stator 314, or makes measurements via electronic gauges strapped to external housing points along the ESP string 20.

A fiber optic sensor 18 uses optical fiber either as the intrinsic sensing element or as an extrinsic means of transmitting signals from remote sensors to the processing unit that receives the signals. Fibers have many uses for remote sensing in the example ESP string 20. Fiber is employed because of its small size and because no electrical power is required downhole. Also, numerous sensors can be multiplexed along a length of a fiber optic strand by assigning different wavelengths of light for each sensor, or by sensing a corresponding time delay as light passes along the fiber through each sensor along the line. The time delay may be determined using an optical time-domain reflectometer or other device.

Fiber optic sensors are immune to electromagnetic interference, which is important downhole given the power being supplied to the submersible motor(s) 24, and fiber optics do not conduct electricity so can be utilized where there is high voltage electricity. Fiber optic sensors can also be constructed with immunity to very high temperatures.

As well as measuring distributed temperatures 334 along its length, an optical fiber can also be used as a sensor to measure strain, pressure and other quantities by modifying the fiber so that the quantity being measured modulates the intensity, phase, polarization, wavelength, or transit time of light in the fiber. Sensors that can vary the intensity of light are the simplest to employ in an ESP string 20, since only a simple source and detector are required. An attractive feature of intrinsic fiber optic sensing is that it can provide distributed sensing over very large distances, as when a well is very deep.

Temperature can be measured by using a fiber that has evanescent loss that varies with temperature, or by analyzing the Raman scattering of the optical fiber. Electrical voltage in the ESP string 20 can be sensed by nonlinear optical effects in specially-doped fiber, which alter the polarization of light as a function of voltage or electric field. Angle measurement sensors can be based on the Sagnac effect.

Optical fiber sensors for distributed temperature sensing 334 and pressure sensing in downhole settings are well suited for this environment when temperatures are too high for semiconductor sensors.

Fiber optic sensors can be used to measure co-located temperature and strain simultaneously, e.g., in an ESP bearing 322, 404, 406, 604, or 606, with very high accuracy using fiber Bragg gratings. This technique is useful when acquiring information from small complex structures.

A fiber optic AC/DC voltage sensor can be used in the example ESP string 20 to sense AC/DC voltage in the middle and high voltage ranges (100-2000 V). The sensor is deployed by inducing measurable amounts of Kerr nonlinearity in single mode optical fiber by exposing a calculated length of fiber to the external electric field. This measurement technique is based on polarimetric detection and high accuracy is achieved in hostile downhole environments.

Electrical power in the ESP string 20 can be measured in a fiber by using a structured bulk fiber ampere sensor coupled with proper signal processing in a polarimetric detection scheme.

When used as a transmission medium for signals from conventional sensors to the surface, extrinsic fiber optic sensors use an optical fiber cable, normally a multimode one, to transmit modulated light from either a non-fiber optical sensor, or an electronic sensor connected to an optical transmitter. Using a fiber to transmit data of extrinsic sensors provides the advantage that the fiber can reach places that are otherwise inaccessible. For example, a fiber can measure temperature inside a hot component of the ESP string 20 by transmitting radiation into a radiation pyrometer located outside the component. Extrinsic sensors can be used in the same way to measure the internal temperature of the submersible motor 24, where the extreme electromagnetic fields present make other measurement techniques impossible.

Fiber optic sensors provide excellent protection of measurement signals from noise corruption. However, some conventional sensors produce electrical output which must be converted into an optical signal for use with fiber. For example, in the case of a platinum resistance thermometer, the temperature changes are translated into resistance changes. The PRT can be outfitted with an electrical power supply. The modulated voltage level at the output of the PRT can then be injected into the optical fiber via a usual type of transmitter. Low-voltage power might need to be provided to the transducer, in this scenario.

Extrinsic sensors can also be used with fiber as the transmission medium to the surface to measure vibration, rotation, displacement, velocity, acceleration, torque, and twisting in the ESP string 20.

An example electronic module can sense vibrations in various planes or combinations of planes, for example the X and Z planes in a 3-dimensional space. In an implementation, vibration canceling modules 354 counteract or dampen vibrations, through vibration canceling technology applied in specific planes.

In one implementation, a sensor of an example vibration module can obtain vibration spectral data up to 1 kHz for a select component along an ESP string 20, for example, for a part of a rotating motor shaft.

In an implementation, an example vibration module can be incorporated into WELLNET Pressure and Temperature gauges or the WELLWATCHER Flux digital sensor array system (Schlumberger Ltd, Houston Tex.).

The example system 20 can also measure temperature profiles along a power cable, e.g., from surface to ESP string 20, using fiber optics or platinum resistance temperature detector(s) (RTDs) 330, e.g., at a pothead.

A rotor vibration sensor 336 may be included to sense relative health of the rotor 308 and its bearings. Each bearing may also have a strain sensor 338 and a proximity sensor 340 to sense wear, as measured by changing alignment or changing tolerances. The rotating shaft 312 of the ESP may have an associated tachometer RPM sensor 342 and a torque sensor 344. The torque sensors 344 may be packaged around motor shafts 312 for monitoring torque and rotational power. Electrically, the ESP may have an electrical current leakage sensor 346 and a wye-point voltage or current imbalance sensor 348. The ESP may also have associated chemical sensors 350, and water cut sensors 352. Additional sensors, e.g., from Wireline Downhole Fluid Analysis tools may be employed to detect gas-oil ratios, solids content, hydrogen sulfide and carbon dioxide concentrations, pH, density, viscosity, and other chemical and physical parameters. The water cut sensors 352 may also be located at various locations in an ESP string for oil purity measurements and for detecting water ingress.

As shown in FIG. 4, the example ESP string 20 may also include a protector 26, which intervenes between motor 24 and pump 22, and which has various components and associated sensors. An example protector 26 may include a shaft 400, shaft seal 402, and shaft bearing 404. At least one shaft bearing may have an associated thrust bearing 406 to bear an axial load of the shaft 400 generated by pump thrust. In an implementation, a thrust bearing is instrumented by addition of temperature, strain, and proximity sensors to monitor status. The protector 26 may also equalize pressure between the motor 24 and pump 22, such as equalization of oil expansion between the two components, or may equalize pressure between the ambient well environment and the interior of the protector 26, and may therefore include at least one expandable bag or bellows chamber 408. The protector 26 may also include a filter 410, when oil in the protector 26 is in communication with motor oil, e.g., the filter 410 keeps motor debris from the protector 26, or, in another or the same implementation, when the interior of the protector 26 equalizes pressure with the ambient well pressure, to keep well fluid debris from entering the interior of the protector 26.

The protector 26 may include many types of sensors to monitor and improve operation, to keep the protector 26 healthy, and to provide high reliability. The protector 26 may include a fiber optic strand 18 to sense distributed temperatures. The fiber optic strand 18 may be the same fiber optic strand 18 running continuously through much or all of the ESP string 20. The protector 26 may also include, e.g., for each bearing, a temperature sensor 328 and a vibration sensor 336. The bag or bellows chamber 408 may have associated differential pressure sensors 412 to measure, for comparison, pressure inside and outside of the bag or bellows chamber 408. A protection mechanism for a protector string employs differential pressure sensors 412 to measure pressure inside and outside the bag or bellows 408 of the protector 26. When a mechanical valve is not protecting the bag or bellows chamber 408, for excessive pressure, the protector 26 may include an electrical pressure relief valve 414 to relieve excess pressure on a signal from a surface sensor analyzer 710, or from a local logic circuit. The electrical relief valve 414 may be used in tandem with conventional mechanical relief valves. Differential pressure sensors 412 monitor stress on the bag, bellows 408, accordion, or other means for equalizing pressure between, e.g., motor oil and external reservoir fluid. When pressure builds up due to a mechanical relief valve failure, the event is detected by differential pressure sensors 412, and the electrical relief valve 414 operates to relieve pressure and prevent protector bag failure or bellows 408 failure.

FIG. 5 shows an exploded view of an example thrust bearing (e.g., 322 or 406). The thrust bearing 322 may be instrumented by addition of at least one temperature sensor 332, a strain sensor 338 (e.g., a load cell), and a proximity sensor 340, to monitor status. The example proximity sensor 340 has high reliability and long functional life because of an absence of mechanical parts in the proximity sensor 340 and lack of physical contact between the proximity sensor 340 and the sensed bearing or shaft. A suitable proximity sensor 340 can measure the variation in distance between the shaft and its support bearing, or between friction interface surfaces of the thrust member 322.

FIG. 6 shows an example pump 22 and associated intake 600. The pump 22 may be a centrifugal pump, but in alternative implementations the example pump 22 may be another type of submersible pump, such as a diaphragm pump or a progressing cavity pump in another type of submersible pump string setup. The example pump 22 has a fluid inlet or intake 600, and a fluid discharge 602. The example pump 22 may have various bearings, such as bearing 604 and bearing 606. Each bearing 604 & 606 may have an associated temperature sensor 332 and vibration sensor 336. The fluid intake 600 may also have at least one pressure sensor 608, a temperature sensor 332, and a vibration sensor 336. Likewise, the fluid discharge 602 may have a respective pressure sensor 608, temperature sensor 332, and vibration sensor 336. The pump 22 may have at least one associated flow sensor 610 to determine a current flow rate of the pump 22 or other volumetric fluid data. The pump 22 may also have associated at least one chemical sensor 350 and at least one water cut sensor 352. These sensors 350 & 352 can detect a gas-oil ratio, solids content, H₂S and CO₂ concentrations, pH, fluid density, and fluid viscosity, for example. The output of the various sensors of the pump 22 may be multiplexed to communicate with the surface using a minimum of communication wires, or a single fiber optic cable.

FIG. 7 shows an example high reliability engine 700 for monitoring various sensors deployed in an ESP string 20, and for controlling components of the ESP string 20 for longer life, high availability, and high reliability. The illustrated high reliability engine 700 is only one example of a sensor-interpretation module and ESP-control module. Other configurations of a monitor-controller could also be used. The example high reliability engine 700 can be situated on the surface, for example hosted by a computer, or can be associated with other components that are on the surface and communicatively coupled with downhole components, such as a variable-speed drive (VSD) 714 or variable frequency drive (VFD). The high reliability engine 700 may also be implemented in a programmable logic controller (PLC). Alternatively, the high reliability engine 700 can be located downhole, as a local module hosted by a computing device that is local to the components of the ESP string 20.

In an implementation, the high reliability engine 700 is coupled with the ESP string 20 via a multiplexer 702 that communicates with many sensors over only a few wires or fibers 18, and then communicates the sensor data to a sensor data input 706 of the high reliability engine 700. In some implementations, the high reliability engine 700 does not use an intervening multiplexer 702. The multiplexer 702 may also include a fiber optics multiplexer 704, e.g., for wavelength-division multiplexing (WDM) so that many sensors can be monitored over a one or a few fiber optic strands. Likewise, the ESP string 20 may have distributed temperature sensing 334 over one or a few fiber optic strands.

The high reliability engine 700 may include a sensor data input 706, and sensor monitoring module 708, an interpretation module 710, and a control module 712. The sensor data input 706 receives signals from the sensors or from the multiplexer 702. The sensors that generate data may include temperature sensors, distributed temperature sensors, vibration sensors, vibration spectral data sensors, pressure sensors, differential pressure sensors, strain sensors, proximity sensors, load cell sensors, dirty filter sensors, bearing wear sensors, positional sensors, rotational speed sensors, torque sensors, electrical leakage detectors, wye-point imbalance sensors, chemical sensors, water cut sensors, and so forth.

The sensor monitoring module 708 keeps track of the data of each individual sensor. The sensor monitoring module 708 may track current real-time sensor data, and also may keep a history of all data or selected data, for a predetermined historical interval. The interpretation module 710 analyzes the sensor data and computes ongoing conclusions about the health of each ESP string component. The interpretation module 710 may signal the control module 712 to modify an operating parameter of the ESP string 20.

The control module 712 has executive control over at least some operating parameters of the ESP string 20, and may adjust the operating parameters to lengthen the life of the downhole hardware components by preventing wear or keeping the operating parameters within safe limits For example, the control module 712 may signal the VSD 714 to change an electrical power parameter, such as voltage, amperage, or frequency being supplied to the submersible motor 24. The change in electrical power modifies operation of the pump 22. For example, a slight slowing of the pump 22 may greatly reduce wear on a bearing, e.g., 322, 404, 406, 604, 606. Or the slight slowing may add life to a pump impeller when an abrasive fluid is being pumped. Or, the pump speed may be adjusted to result in a safe operating temperature of the motor 24, protector 26, or pump 22.

Upon receiving signals from the interpretation module 710, the control module 712 may also apply anti-vibration mechanical waves or acoustic waves via the vibration canceling modules 354. In an implementation, the vibration canceling modules 354 cancel out vibrations in a selected vibration plane.

The control module 712, upon being signaled by the interpretation module 710, may also decrease a pressure, either by tapering off the output of the pump 22 or by actuating a valve, such as electrical pressure relief valve 414, which can spare a bellows/bag/chamber 408 from excessive pressure. The control module 712 may also actuate other valves to divert or rearrange a flow path, in order to improve the operation or increase the lifespan of the components of the ESP string 20. There are many other valves, solenoids, actuators, coils, motors, and electrical parameters that the control module 712 can control in order to improve the performance of the ESP string 20 or add life to a component. For example, on sensing wear of a thrust washer or bearing 322 or 406, the control module 712 may adjust a thrust washer pad, moving the worn pad closer to a contacting surface. The control module 712 can perform many other interventions, such as adjusting pump operation to suit the physical characteristics of the fluid being pumped, run a self-cleaning cycle in the ESP string 20, activate additional tests and sensors when called for, change position of parts to compensate for wear, perform built-in maintenance measures, dispense lubricants, clean an optical window, switch to a spare or a reserve part (e.g., electrical), and many other remote-control interventions, prompted by the sensors and the interpretation module 710, that improve operation or lengthen the lifespan of a component of the ESP string 20.

FIG. 8 shows an example computing or hardware environment, e.g., example device 800, for hosting the high reliability engine 700 of FIG. 7. Thus, FIG. 8 illustrates an example device 800 that can be implemented to monitor and analyze sensor data, and control or intervene to help provide improved operation, high reliability, and high-availability to an ESP string 20. The shown example device 800 is only one example of a computing device or programmable device, and is not intended to suggest any limitation as to scope of use or functionality of the example device 800 and/or its possible architectures. Neither should example device 800 be interpreted as having any dependency or requirement relating to any one or a combination of components illustrated in the example device 800.

Example device 800 includes one or more processors or processing units 802, one or more memory components 804, one or more input/output (I/O) devices 806, a bus 808 that allows the various components and devices to communicate with each other, and includes local data storage 810, among other components.

Memory 804 generally represents one or more volatile data storage media. Memory component 804 can include volatile media (such as random access memory (RAM)) and/or nonvolatile media (such as read only memory (ROM), flash memory, and so forth).

Bus 808 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. Bus 808 can include wired and/or wireless buses.

Local data storage 810 can include fixed media (e.g., RAM, ROM, a fixed hard drive, etc.) as well as removable media (e.g., a flash memory drive, a removable hard drive, optical disks, magnetic disks, and so forth).

One or more input/output devices 806 can allow a user to enter commands and information to example device 800, and also allow information to be presented to the user and/or other components or devices. Examples of input devices include a keyboard, a cursor control device (e.g., a mouse), a microphone, a scanner, and so forth. Examples of output devices include a display device (e.g., a monitor or projector), speakers, a printer, a network card, and so forth.

A user interface device may also communicate via a user interface (UI) controller 812, which may connect with the UI device either directly or through the bus 808.

A network interface 814 communicates with hardware, such as the sensors, valves 414, multiplexer 702 and/or 704, vibration canceling modules 354, VSD 714, VFD, and so forth.

A media drive/interface 816 accepts media 818, such as flash drives, optical disks, removable hard drives, software products, etc. Logic, computing instructions, or a software program comprising elements of the high reliability engine 700 may reside on removable media 818 readable by the media drive/interface 816.

Various techniques and the modules of the high reliability engine 700 may be described herein in the general context of software or program modules, or the techniques and modules may be implemented in pure computing hardware. Software generally includes routines, programs, objects, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. An implementation of these modules and techniques may be stored on or transmitted across some form of tangible computer readable media. Computer readable media can be any available data storage medium or media that is tangible and can be accessed by a computing device. Computer readable media may thus comprise computer storage media.

“Computer storage media” include volatile and non-volatile, removable and non-removable tangible media implemented for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible medium which can be used to store the desired information, and which can be accessed by a computer.

Example Method

FIG. 9 is an example method 900 of improving performance and reliability of an ESP string. In the flow diagram, operations are represented by individual blocks. The example method may be performed by hardware and software elements, such as the example high reliability engine 700.

At block 902, an electric submersible pump (ESP) string is outfitted with at least one motor and a sensor associated with at least a shaft bearing or a rotor bearing of each section of the ESP string.

At block 904, sensor data is dynamically tracked by a monitoring module.

At block 906, an operating parameter of a component of the ESP string is changed by a control module, based on the dynamic tracking of the sensor data.

Conclusion

Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the subject matter. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function. 

1. A system, comprising: an electric submersible pump (ESP) string, including at least one ESP motor; a sensor associated with at least a shaft bearing or a rotor bearing of each section of the ESP string; a monitoring module for dynamically tracking data of each sensor; and a control module for changing an operating parameter of a component of the ESP string based on the dynamic tracking of the sensor data.
 2. The system of claim 1, further comprising a fiber optic strand to perform distributed sensing of temperatures along the ESP string, the control module changing an operating parameter of at least one component of the ESP string based on the distributed sensing of the temperatures.
 3. The system of claim 2, wherein the fiber optic strand runs internally in at least one motor stator of the ESP string.
 4. The system of claim 2, wherein the distributed sensing of temperature using the fiber optic strand includes sensing a temperature associated with at least a shaft bearing or a rotor bearing of the ESP string.
 5. The system of claim 4, further comprising a vibration sensor to dynamically track vibrations generated by the ESP string.
 6. The system of claim 5, wherein a vibration module obtains vibration spectral data up to 1 kHz for a select component along the ESP string.
 7. The system of claim 5, wherein each vibration sensor dynamically tracks a vibration associated with a pump bearing or a motor bearing of the ESP string.
 8. The system of claim 7, wherein the control module changes an operating parameter of at least one component of the ESP string based on analysis of at least one temperature and at least one vibration in the ESP string.
 9. The system of claim 1, further comprising a fiber optic strand to measure a distributed temperature profile or a platinum resistive thermocouple device (RTD) to measure a temperature of a power cable of the ESP string or along a motor lead extension (MLE) cable of the ESP string.
 10. The system of claim 1, further comprising a tachometer (RPM) sensor or a torque sensor packaged around at least a shaft for monitoring a rotational speed and a torque of the shaft.
 11. The system of claim 1, further comprising at least a water cut sensor or at least a chemical sensor located along the ESP string to perform oil purity measurements or chemical measurements.
 12. The system of claim 1, further comprising a pressure sensor located in the ESP string to perform a pressure measurement.
 13. The system of claim 12, wherein at least one pressure sensor measures a differential pressure inside and outside of a bellows in the ESP string.
 14. The system of claim 13, further comprising an electrical relief valve in tandem with a mechanical relief valve for relieving a pressure in the bellows.
 15. The system of claim 1, further comprising an electrical current leakage sensor.
 16. The system of claim 1, further comprising a wye-point imbalance detector for detecting an unbalanced phase in a wye system.
 17. The system of claim 1, further comprising a thrust member sensor to measure one of a temperature, a strain, or a proximity of a thrust member to a thrust member runner in the ESP string.
 18. A system, comprising: an electric submersible pump (ESP); a control module to change an operating parameter of a component of the ESP based on dynamic tracking of data from multiple types of sensors arrayed along the ESP; a sensor associated with at least a bearing of each component of the ESP; and a sensor selected from the group of sensors consisting of bearing temperature sensors, bearing vibration sensors, stator temperature sensors, distributed temperature profile sensors, power cable temperature profile sensors, motor lead temperature profile sensors, shaft RPM sensors, shaft torque sensors, water cut sensors, water ingress sensors, chemical sensors, bellows pressure sensors, thrust bearing temperature sensors, thrust bearing strain sensors, thrust bearing proximity sensors, electrical current leakage sensors, and wye-point imbalance sensors.
 19. The system of claim 18, wherein the multiple types of sensors arrayed along the ESP are multiplexed along the length of a fiber optic strand by one of: assigning different wavelengths of light for each sensor, or sensing a time delay as light passes along the fiber through each sensor, wherein an optical time-domain reflectometer determines the time delay.
 20. The system of claim 18, wherein a control module changes an operating characteristic of at least a segment of the ESP based on monitoring the multiplexed sensors, by varying a power, a voltage, an amperage, a frequency, a pump speed, a motor speed, a valve state, a pressure, a flow, a temperature, or a vibration in a selected spatial plane, of the at least one component of the ESP. 